Convert 21/40 to a percent.

Divide the numerator by the denominator.

Multiply your decimal answer by 100.

http://www.mathsisfun.com/converting-fractions-percents.html

21/40*100=52.5%

Right.

To convert a fraction to a percent, you need to multiply it by 100. Here's how you can do it:

Step 1: Divide the numerator (top number) of the fraction by the denominator (bottom number):

21 ÷ 40 = 0.525

Step 2: Multiply the result from step 1 by 100 to get the percent:

0.525 × 100 = 52.5%

Therefore, 21/40 is equal to 52.5% when expressed as a percent.